The field of this invention is the application of systemic pesticides. More particularly, this invention pertains to an improved process for the internal placement of systemic insecticides, fungicides, acaricides or nematicides into asexual plant propagules, such as tubers, corms, bulbs, stolons, rhizomes, and stems.
Systemic pesticides, commonly referred to as systemics, are chemicals which are toxic to pests when ingested, and which are readily absorbed by plants and diffused throughout the plants in their sap streams. Systemics are typically introduced into plants either by application to the leaves of the plants, or to the root systems thereof. When insects feed on plants which have been impregnated with systemics, they ingest the systemics and are poisoned thereby, provided the concentrations in the sap streams are maintained at levels sufficiently high to be lethal.
Various devices and systems for the application of systemics to plants, seeds, and soil, have been developed in the art. U.S. Pat. No. 5,527,366 discloses a method of applying an herbicide to plants which includes delivering a liquid herbicide solution to the plant foliage in a high pressure jet stream to physically disrupt the surface of the foliage. U.S. Pat. No. 4,291,497 describes a method of introducing a chemical agent into plants by spraying or dipping the plant organs into the agent and allowing the agent to penetrate the plant system. U.S. Pat. Nos. 4,994,487 and 5,575,224 disclose a device for injecting a liquid pesticide (fungicide and herbicide, respectively) into the soil adjacent to the root system of plants. U.S. Pat. No. 4,356,934 discloses a seed treatment method which includes spraying of an emulsion containing an insecticide, fungicide or bactericide, onto the seed prior to planting. U.S. Pat. No. 4,596,206 discloses an apparatus for treatment of seeds with a liquid insecticide-fungicide, prior to planting.
A disadvantage of the known methods of applying insecticides to plants is the potential exposure to humans resulting from handling the treated plants.
An advantage of the process of the present invention is the application of the systemic insecticide, fungicide, acaricide or nematicide to the asexual propagules of plants so that it is absorbed by the root systems of the plants, and is isolated from direct contact with the air, soil, water and humans.
The present invention provides an improved process for applying systemic pesticides to plants wherein the improvement comprises incorporating the pesticide internally into an asexual propagule of the plant. The systemic pesticides include systemic insecticides, systemic fungicides, systemic acaricides and systemic nematicides. Many such systemic pesticides are commercially available such as imidacloprid (available from Bayer Corporation under the Admire, Confidor, Gaucho, Merit, Premier, Premise and Provado names), fenamiphos (available from Bayer Corporation under the Nemacur name) and triadimefon (available from Bayer Corporation under the Bayleton name). Additional commercially available systemic pesticides are described in the Farm Chemicals Handbook ""99, vol. 85. The asexual plant propagules include the plant tubers, corms, bulbs, stolons, rhizomes, and stems.
The present invention provides a process for application of a systemic pesticide to plants. Further, the present invention includes internal placement of the systemic in the plants. In particular, the systemic is placed inside of an asexual plant propagule and the systemic is thereby absorbed by the shoots and foliage growing from the propagule.
The systemic pesticide includes known insecticides, fungicides, acaricides or nematicides. In a preferred embodiment, the insecticide is imidacloprid. The asexual plant propagules include the plant tubers, corms, bulbs, stolons, rhizomes, and stems. Insertion of the systemic pesticide into the asexual plant propagule may be accomplished by hand or by various automated injection devices known in the art. For example, U.S. Pat. No. 4,011,685 discloses a plant injection device which comprises an injection-type needle. The needle portion of the device may be inserted into the plant either by applying force, or by drilling a hole in the plant and inserting the needle therein. U.S. Pat. No. 4,899,488 describes a spray nozzle-type tool for internal application of a liquid agent to plant life.
In an embodiment of the invention, the systemic pesticide is a formulation which contains a known insecticide, fungicide, acaricide or nematicide as an active ingredient. In a preferred embodiment, the formulation includes imidacloprid as the insecticidal active ingredient. In addition to the active ingredient, the formulation may also include an adjuvant.
As is known in the art, an adjuvant is used in a formulation to aid the operation or improve the effectiveness of the pesticide. As is known in the art, the term xe2x80x9cadjuvantxe2x80x9d includes such materials, as wetting agents, spreaders, emulsifiers, dispersing agents, foaming adjuvants, foam suppressants, penetrants, thickeners, antifreeze agents, correctives, fillers and carriers. A spray adjuvant may contain one or more surfactants, solvents, solubilizers, buffering agents, and stickers needed to formulate a specific type adjuvant. Suitable adjuvants are known and described, for example, in FARM CHEMICALS HANDBOOK ""99 and in A GUIDE TO AGRICULTURAL SPRAY ADJUVANTS used in the United States, 5th Edition, Thomson, 1998.